Fusible element



June 6, 1950 J. H. REGER 2,510,756

FUSIBLE ELEMENT Filed March 18, 1948 Z0 INVENTOR. JuHH H. REBER BY I I I l f ATTORNEY Patented June 6, 1950 UNITED STATES PATENT OFFICE FUSIBLE ELEMENT John H. Reger, Devon, Conn.

Application March 18, 1948, Serial No. 15,552

This invention relates to fusible elements or devices and has particular relation to an element or device especially designed for use in fire extinguishers. 7

An object of the invention is to provide a fusible element or device designed to collapse under heat and pressure and which is so constructed that it retains its shape and size under a considerable degree of pressure.

Another object is to provide an element or device having the characteristics stated and which is constructed to withstand pressure and heat to a predetermined point and then on further heating to collapse suddenly and rather completely.

Other objects and advantages of the invention will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawing wherein satisfactory embodiments of the invention are shown. However, it is to be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention and the scope of the appended claims.

In the drawing:

Fig. 1 is an enlarged side elevational view of a fusible element constructed in accordance with the invention;

Fig. 2 is a top plan view of the element, the view being on the scale of Fig. 1;

Fig. 3 is a central vertical sectional view through the element of Fig. '1;

Fig. 4 is a plan view of the element in collapsed or crushed condition;

Fig. 5 is an edge elevational view of the element as shown in Fig. 4;

Fig. 6 is a'view similar to Fig. 2 but showing a slight modification; and

Fig. 7 is a side elevational view of the modified structure shown in Fig. 6.

The fusible element of the invention is especially designed for use in a fire extinguisher or the like. One example of such use is disclosed in my parent application Serial Number 682,798 filed July 11, 1946, of which this present application is a continuation in part. Also, my improved fusible element is shown as in use in my copending application Serial Number 15,551, filed March 18, 1948.

Referring in detail to the drawings and at first more particularly to Figs. 1-5, my improved fusible element is generally designated I0. This element) comprises a body portion ll having a recess l2 drilled or otherwise formed therein and 6 Claims. (01. 169-42) 2 extending therethrough or extending substantially therethrough. 'This recess is in the longitudinal center line of the body and receives a plurality of steel balls l3, or balls of other relatively incompressible material.

As shown, the socket or recess I2 is receiving three of the balls I3 and the latter are in alignment, disposed one on top of the other, and the aggregate of their diameters is the same, or substantially the same, or slightly greater than the thickness of the body ll. Further, it is noted that transversely the recess I2 is of the diameter or substantially of the diameter of the balls I3 whereby when they are located in the recess they are retained in alignment and in relation one on top of the other.

The body ll includes radially thickened portions I4 and such portions are located about the respective balls l3 whereby the body is radially or laterally strengthened in its portions directly opposite or in radial alignment with the respectiveballs. Preferably, the body II is of Barnabas- Woods material or Cerro Bend. Melting of the body-then occurs at a temperature of approximately F.

As will later appear, element I0 is of considerable strength in a direction measured along its length whereby to withstand considerable pressure in such direction without crushing or collapsing. In the use of the element l0, it is customarily held under pressure and such pressure is exerted against the balls while the latter are kept in alignment and so such pressure is withstood by the element, it being understood that the balls are all hard metal or the like.

In any event, the balls are of harder material than the body I l and have a much higher melting point. The low melting point of the fusible body ll of the element In is desirable especially when the element is used in a fire extinguisher in order that the latter will function or operate at the earliest possible moment after heat is applied to the element whereby the fire extinguisher will function in the early stages of a fire and. before the latter has a chance to spread or gain any considerable headway.

As explained in my parent application and my companion application above identified, when the element of the invention is in use it is withstanding the pressure of a spring and also of a fire extinguishing fluid which is kept under pressure. Thus, while in use, the fusible element ll] of the invention is generally under considerable pressure but this pressure is exerted through the incompressible aligned balls I3. As long as above mentioned pressures. body suddenly and completely collapses so as to these balls remain in alignment, the pressure is transmitted from one to the other of the balls and they provide an incompressible column.

Assuming that the present element is in place in a fire extinguisher and that the latter is loaded, on heat reaching the present element to sufiicient degree, the body H softens rapidly. At this time, the body will be under considerable pressure as suggested above and as the body softens the balls [3 are permitted to go out of alignment or move out of alignment and they do move laterally or radially.

As this occurs, there is a very rapid collapse of the element ll]. Thus, the element may very rapidly collapse from the height of Figs. 1 and 3 to substantially that shown in Fig. as'the balls I3 move radially or laterally .of one another and come into a side-by-side relation in the same plane (see particularly Figs. 4 and 5). This is true since when the balls move 01f of one another or out of the column or arrangement, they no longer provide the rigid support to withstand the pressureon-the element and they permit of lateral movement 'of'the balls and the element collapses rather suddenly and thoroughly.

Where the element is used in an extinguisher .and the extinguishing fluid is passing in the vi- -.cinity.of the element, the amount of collapse oi the element will depend to some extent on the rapidity with which the element is cooled by the escaping fluid or the fire extinguishing fluid being discharged. Generally, the element will collapse .to approximately one-third its original height, in which instanceall three of the balls I3 will be at' the-same level or in the same plane and in a side-by-side relation as suggested in Figs. 4

and 5 wherein the-collapsing body of the element is designated I5.

Thus, it will be understood that the present element remains extremely rigid to any pressure applied'longitudinally of it until the balls F3 are .permitted'to move laterally with respect to'one another. Then thebody H of the element being softened by heat, the balls are not retained against lateral movement and slipping off .one another leave the softened body 11 totake'the Thereupon, the

permit a fire extinguisher to function. For 'ex- .ample this collapse of the element in my applications above mentioned permits the opening of a valve.

Figs. (Sand '7 show a slight modificationof a fusible element and in said figures the fusible element is generally :indicated at It. This element includes a body I having a recess or opening 18 drilled or otherwise formed therein and extending therethrough or extending substan- ,tially therethrough. This recess or opening l8 of Figs 6 and 7 corresponds with the-recess or opening l2 of Figs. 1, 2 and 3 and is for the same purpose. Thus, opening is is shown. as receiving three relatively hard-balls lgand therecess transversely is substantially of the diameter of the balls whereby the latter are retained in position one on the other. a

The aggregate diameters of the balls lfiissubstantially the same as the overall height of the body H or the .lengthof the recess l8. Body :l'l includes fiat lower and upper ends-26 and 2! and for a distance slightly upwardlyfrom the lower fiat surface 29 the body 1'! isof uniform diameter and then ittapers inwardly toward its upper -flat surfaced-has at.2 2. Thus, the body is of less .diametertoward its upperend'or surface 2|.

scribed will cause a sudden -;and complete collapse of the body l6 resulting in the'balls being disposed in side-by-side relation as illustrated in the body l5 (Figs. 4 and 5) and which body represents the collapsed body ll of the element I0.

From the above description, it will be clear that I have .provided a fusible element so constructed as'towithstand a tremendous compressive force applied to it in the direction of its length or in a manner to press one of the incompressible balls l3 or 19 of Figs. 3 and '7 against vtheothers thereof. However, on softeniIigOf the body material "of either of -the elements It or IE so that the balls may shift'laterally or out of alignment, then the applied pressure-on-the heat softened body of the element will result in rapid and rather complete crushing or collapsing of such'body.

Having thus set forth the'natureof my invention, what I.claim is:

1; A fusible element for use in 1a fire extinguishensaidelement-comprising a'bodyof fusible material having a recessextending substantially entirely therethrough, a series of balls disposed in said recess, the diameter of said recess and said balls being such that the latter are disposed one on the other in said recess, said recess being of substantially uniform -diameter and :openingthrough at'least oneend of said body whereby all of said balls may be placed therein from said end of the body and the collective diameters of saidballs being substantially equal to the depth of said recess.

.2. The element asin claim 1 whereinsaidba-lls are of a substantially incompressible material having a heat softening point materially higher than that of 1 said :body.

3. A fusible element for use in afire extinguisher, said element comprising an elongated one-piece body of fusible-material having a recess extending longitudinally substantially entirely'therethioug-h, a seriesof balls of'substantially non-fusible material in said recess, said recess and said-balls 'of suchdiameter that the latter are disposed one on the other in saidrecess, said recess'being of substantially uniform diameter and opening through at least one end of-said body whereby all of said balls maybe placed in the recess from said end "thereofyand the collective diameter of said ."balls being substantially equal to the .leng'thof said recess.

4. A fusible :element :for use in a fire extin- .guishenxsaid'element comprising a-bo'dy of fusible material having a recess extending substantially entirely th'erethrough, series of .balls :disposed in said recess, the diameter of said recess and said balls-beingssuchthat the latter are disposed one on the other-in said recess, the collective diameters .of said balls being substantially equal to the depth of said recess, and said body radially thickened-in its portions radially :of :the respective balls.

5. A fusible element for use in :a fire extinguisher, saideleinentcomprisinga body of fusible material having a recess extending'substantially entirely therethrough, a series of balls disposed in said recess, the diameter of said recess and said balls being such that the latter are disposed one on the other in said recess, the collective diameters of said balls being substantially equal to the depth of said recess, and said body externally tapered for a substantial portion of its length through one of its ends whereby such end is of less diameter than the other end of the body.

6. A fusible element for use in a fire extinguisher, said element comprising a body of fusible material having a recess extending substantially entirely therethrough, a series of balls in said recess, the diameter of said recess and said balls being such that the latter are disposed one on the other in said recess, the collective diameters of said balls being substantially equal to the depth or said recess, said body having substantially fiat ends, and said body of a constant diameter in one end portion and then tapered inwardly throughout its length to its other end whereby such other end is of substantially less diameter than the first mentioned end.

JOHN H. REGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date .15 1,231,439 Simonds et a1. June 26, 1917 1,929,333 Rowley a. Oct. 3. 1933 

